Immunological crossreactivity between the class I epitope of streptococcal M protein and myosin.
Immunological crossreactivity between the class I epitope of streptococcal M protein and myosin.
复制标题
链球菌 M 蛋白的 I 类表位与肌球蛋白之间的免疫交叉反应性。
DOI：
10.1007/978-1-4899-1825-3_208
复制
发表时间：
1997
影响因子：
--
通讯作者：
Quinn,A
中科院分区：
文献类型：
--
作者：
Cunningham,MW;Quinn,A
急性风湿热（ARF）是一种炎症性疾病，是A组链球菌感染的延迟后遗症。ARF的发病机制被认为是由自身免疫机制介导的19。心肌肌球蛋白已被鉴定为心脏交叉反应性抗链球菌自身抗体识别的心脏抗原之一8，15。链球菌M蛋白，一种α-螺旋卷曲螺旋蛋白，在结构上和免疫学上模拟宿主组织抗原，特别是肌球蛋白7，9-11，17，18。虽然A组链球菌M蛋白有80多种不同的血清学类型，但流行病学研究表明，只有有限数量的M蛋白血清型与ARF爆发有关4。这表明某些M蛋白血清型可能比其他血清型更具致风湿性。Bessen及其同事最近提出了一种分类方案，其中根据表面暴露的M蛋白表位的表达对链球菌血清型进行分组2。研究表明，与大多数ARF爆发相关的M血清型共享由Mab探针10 B6和10 F5定义的表位（I类），其序列定位于6型M蛋白C重复区内的15个氨基酸片段14。其余血清型（II类）要么缺乏该表位，要么在这些菌株中该决定簇在结构上不可接近。在被指定为I类的那些血清型和先前由Widdowson分类为MAP I的那些血清型之间存在密切的平行21，22。I类链球菌中只有某些血清型是致风湿性的，这一事实意味着这些微生物具有能够诱导ARF 2的表型。这部分得到了最近出版物的支持，其中显示ARF患者的血清含有高水平的I类表位抗体，表明他们的疾病是I类链球菌感染的结果3。
Acute rheumatic fever (ARF) is an inflammatory disease that occurs as a delayed sequel to group A streptococcal infection. The pathogenesis of ARF is thought to be mediated by autoimmune mechanisms19. Cardiac myosin has been identified as one of the cardiac antigens recognized by heart-crossreactive anti-streptococcal autoantibodies8, 15. Streptococcal M protein, an a-helical coiled-coil protein, structurally and immunologically mimics host tissue antigens, in particular myosin7, 9–11, 17, 18. While there are more than 80 different serological types of group A streptococcal M protein, epidemiological studies indicate that only a limited number of M protein serotypes are associated with ARF outbreaks4. This suggests that certain M protein serotypes may be more rheumatogenic than others. A recent classification scheme has been proposed by Bessen and colleagues in which streptococcal serotypes were grouped based on the expression of a surface exposed M protein epitope2. It was demonstrated that the M serotypes associated with the majority of ARF outbreaks shared an epitope (class I) defined by Mab probes 10B6 and 10F5, whose sequence was localized to a 15 amino acid fragment within the C repeat region of the type 6 M protein14. The remaining serotypes (class II) either lack this epitope or the determinant is structurally inaccessible in those strains. There was a close parallel between those serotypes designated as class I and those serotypes previously classified by Widdowson as MAP I21, 22. The fact that only certain serotypes within class I streptococci are rheumatogenic implies that these organisms are of a phenotype that is capable of inducing ARF2. This is in part supported by a recent publication in which it was shown that sera of ARF patients contained high levels of antibodies to the class I epitope, suggesting that their disease was the result of an infection by a class I streptococcus3.